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Vibration isolation in Power Hammer

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Hi! Fellow Forgers,

In our existing new forging hammer we are experiencing that there is great amount of vibration being transmitted to nearby areas. While building the foundation we used vibration isolation pads of Neoprene Rubber along with sand and boulders under the foundation, a 4 " air gap was also used on all four sides of the foundation to isolate the foundation from the ground. However, it seems that vibration is being transmitted from the bottom of the foundation only as the air gap would eliminate any vibration from the sides. Can somebody suggest any solution to this problem without disturbing the foundation. I was told by somebody that there are companies which drill holes in the ground at depths greater than the depth of the foundation. Help will be greatly appreciated as we have stopped the functioning of the hammer till this problem is solved.


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Hi Rambo, could we have some pictures of the hammer and foundation, it would be easier to try to help you !
I'm sure I'm not the only one in here enjoying pictures of e-friends' big boys toys...
Is there a way to lift the foudation out of its hole and put some more antivibrating stuff underneath ?
And please all of you, excuse my English as I'm a French-frog...

Edited by Madmike
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Mad Mike, Your English is as good as mine, but then I do speak American:)

Under big hammers, there is usually a deep concrete foundation, going down to very solid hard pan earth or bedrock. This foundation is usually isolated from the surrounding slab as you have done. The next item will usually be a timber pad, often several ( ours was anout a meter thick) layers at 90 degrees to each other. These timbers are usually 10" to 12" square on big hammers like yours. (250 to 300mm) We used oak. These were soaked in creosoate, a preservative. They were cross bolted with tie bolts. Then the anvil sub-base, then the anvil.
Rambo, what ratio is the anvil to the hammer. You need at least 10 : 1, with a higher anvil to ram better.

Last but not least, if the water table is high, and the foundation is sitting in wet soil, the foundation will act like a big piston and send hydraulic pressure waves out to the surroundings.

We had this problem as Our forge shop sat on an ancient sand and river sediment bank. The water table was high. We run that concrete foundation down to the bedrock. That was about 90' (28 meters) deep! The bedrock was floating on more sand and sediments. The hunk of bedrock was about 27 city blocks long, by about 10 city blocks in the middle. We knew this since you could feel the vibrations when our biggest hammer hit, anywhere above that rock. Our hammer was at one end and this made the vibrations worst at the opposite end. It was a 25,000 #( 11348 Kg) Erie steam drop hammer. This hammer was suped up at the factory as it ran at 145#, 345F steam, and had an extra long stroke.
The city authorities made a law that we could only run our 3 biggest hammers during daylight hours as they woke folks up!

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Hi!, I do not see an easy way to lift the foundation to place springs etc under the foundation. The hammer is different from other die forging hammers, the anvil has been placed in a pit in the foundation, i.e. the hammer body is not fixed to the anvil but to the foundation. Instead of timber, neoprene rubber pads have been placed under the anvil as well as under the foundation. The spec of anvil and the falling weight are
1. Weight of anvil 200,000 lb.
2. Falling weight of ram + rod + upper die 18,000 lb.
I am enclosing a schematic of the drawing of the foundation and a 3D view of the hammer for better understanding.
Can you suggest if drilling holes in the ground till a depth of the foundation or more will be heplfull, probabaly some 75 ft away from the hammer. Or is there any other solution without having to move the anvil or foundation.

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Edited by rambo
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The question I have is not how to dampen the vibration, but why? It seems you have plenty of isolation already. The effort and expense involved in MORE isolation may not be worth it. There is going to be an acceptable level, an almost unavoidable level of transfer of vibration with such a big hammer. All of the large industrial hammers I know of shake the ground a bit.

Is the vibration causing problems? Would it be easier to isolate the other equipment around the hammer to prevent the vibes from effecting them?

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